A university student finds himself wrapped up in the bizarre world of his next door neighbor, learning about his history and relationship with a girl who changed his life.

It's three years after the events of the original Battle Royale, and Shuya Nanahara is now an internationally-known terrorist determined to bring down the government. His terrorist group, Wild Seven, stages an attack that levels several buildings in Tokyo on Christmas Day, killing 8000 people. In order for the government to study the benefits of "teamwork", the new students work in pairs, with their collars electronically linked so that if one of them is killed, the other dies as well. They must kill Nanahara in three days - or die.

A rock band writes a song called "Fish Story" that is foretold to save the world. The song exceeds the boundaries of space and time and ties people and their stories together.

Two Osaka comedians, Makoto (Tomomitsu Yamaguchi) and Kinta (Go Morita), are riding bicycles in Tokyo when they're hit by a dump truck. They regain consciousness in 1945, but not of their own bodies. Somehow, their souls have been transported into the bodies of two tokkotai (special forces, or "kamikaze") pilots. Having grown up in a peaceful, carefree Japan, the two comedians experience severe disorientation at having to suddenly deal with the realities of war. They attempt to escape their squadron, knowing that Japan will eventually lose the war, but are nevertheless moved by the young men they meet, all of whom have very different opinions about their fate and the responsibilities that have been placed upon them.